1. Field of the Invention
The present invention relates to a fixing component for fixing an optical fiber cord to an optical connector.
2. Description of Related Art
The optical fiber cord has a tension member arranged around a fiber core, and a sheath arranged therearound, as a basic structure. For connection of such an optical fiber cord to an optical connector, it is necessary to hold a stable transmission characteristic even with tensile strength acting backward on the cord. Therefore, in the past, on an outer peripheral surface of a rear end part of an optical connector (connector housing) with fiber core inserted thereto, there were put the sheath and the tension member peeled off in advance from the fiber core, and separate fixing components (metallic rings) were put on an outside of the tension member and an outside of the sheath, and by caulking the fixing components, the tension member and the sheath were fixed in a press-fitting manner to the optical connector.
However, in consideration of reduction of component cost as well as of simplification of assembly work, it is preferable, rather than fixing the tension member and the sheath in a press-fitting manner to the optical connector by separate fixing components as described, to fix them in a lump. Therefore, recently, there is employed such a fixing component 30 as shown in FIGS. 5A to 5D. FIG. 5A is a front view of the fixing component 30, FIG. 5B is a plan view of the component 30, FIG. 5C is a side view of the component 30, and FIG. 5D is a rear view of the component 30. This fixing component 30 is integrally formed, as shown in FIG. 5B and FIG. 5C, with a tension member fixing portion 31 for fixing a tension member of an optical fiber cord in a press-fitting manner, and a sheath fixing portion 32 for fixing a sheath of the cord in a press-fitting manner. Moreover, as shown in FIG. 5A and FIG. 5D, the tension member fixing portion 31 and the sheath fixing portion 32 are both configured as a metallic tube of a substantially elliptic form in cross section. The fixing component 30 is adapted, as shown in FIG. 6, by putting the tension member fixing portion 31 on the outside of a tension member 35 of an optical fiber cord 34 put on an outer peripheral surface of a rear end part of an optical connector (connector housing) 33, putting the sheath fixing portion 32 on the outside of a sheath 36 put on the outer peripheral surface of the rear end part, and caulking them in a lump, so that the tension member 35 and the sheath 36 can be press-fitted to be fixed in a lump to the optical connector 33. Although in FIG. 6 a step is formed between the tension member fixing portion 31 and the sheath fixing portion 32, there is a case of caulking not to form a step.
The conventional fixing component shown in FIG. 5A to FIG. 5D has the following problems:
(1) For a structural reason of the optical connector, outside diameters of the tension member fixing portion and the sheath fixing portion of the fixing component must be different, and there develops a strain when the two fixing portions different in outside diameter are caulked simultaneously. More specifically, because of no escaping place for the strain developed in the tension member fixing portion, part (excessive part) of that fixing portion is caused to bulge like a wen at the sheath fixing portion side. As a result, the caulking at either or both of the tension member fixing portion and the sheath fixing portion becomes incomplete. Further, it needs a very strong force for the caulking to be complete.
(2) In order for the tension member fixing portion to have an identical cross sectional form before and after the caulking, it is necessary to evenly caulk the entirety from outside toward the center (it is necessary to evenly caulk in the direction of arrow in FIG. 5A). On the other hand, for the sheath fixing portion, such a caulking is necessary that the sheath is pinched from the left and right (it is necessary to caulk in the direction of arrow in FIG. 5D). In other words, between the tension member fixing portion and the sheath fixing portion, the caulking force and caulking direction are different. Therefore, when the tension member fixing portion and the sheath fixing portion are caulked in a lump, the two fixing portions have different contraction due to the caulking, so that the above-noted strain is yet increased.
It is an object of the present invention to provide a fixing component which is free from incomplete caulking even when a tension member fixing portion and a sheath fixing portion that are different in outside diameter are caulked in a lump, and does not need very strong forces for the caulking.
According to an aspect of the present invention, there is provided an optical fiber cord fixing component which is integrally formed with a tension member fixing portion for fixing, in a press-fitting manner, a tension member of an optical fiber cord put on an outer peripheral surface of an optical connector to the outer peripheral surface by caulking, and a sheath fixing portion for fixing, in a press-fitting manner, a sheath of the cord put on the outer peripheral surface of the connector to the outer peripheral surface by caulking, and which is formed, between the tension member fixing portion and the sheath fixing portion, with a slit capable of absorbing a deformation of either or both of the tension member fixing portion and the sheath fixing portion by the caulking.